Indexing device



D. H. MILLS INDEXING vDEVICE April 3, 1951 5 Sheets-Sheet l Filed Aug. 25, "1945 l HI/Ez-ZDF Donald Howard/fills D. H. MILLS INDEXING' DEVICE:

April V3, 1951 rlled Aug 25 1945 D. H. MILLS April 3, 1951 INDEXING DEVICE ls sheets-sheet s Filed Aug. 25. 1945 y HM w Patented Apr. 3, 1951 L UNITED STATES PATENT OFFICE Y 2,547,533 f INDEXING DEVICE Donald Howard Mills, Fort Wayne, Ind. Application August 25, 1945, Serial No. 612,687

17 claims. (o1. 'i4-10.15)

`to provide a control system and apparatus devoid of the diiliculties mentioned above and of general use in a wide variety of electrical and mechanical equipment, such as power and control'equipment and especially tunable apparatus such as radio transmitters and receivers.

Another object of the present invention is to provide novel apparatus for controlling an electrical circuit.

Another object of the present invention is to provide preset tuning apparatus especially adapted for use in compact radio equipment such `as automobile radios and low cost portable radios suitable for home use.

A more specific object of the present invention is to provide e, novel means for tuning a radio receiver to any one of a plurality of predetermined stations. f

A still further object of the present invention is to provide a novel adjusting device for selective :adjustment of any one of a plurality of tuning positions at will, which adjustment is free from drift or backlash normally caused by lfrequent, `successive operations of the device.

A still further object of the present invention is to provide a novel tuning apparatus that is relatively simple in construction and that involves relatively few and small parts making the apparatus light in weight and compact so as to make it especially adaptable for auto, aircraft and portable radios.

A still further Object of the present invention is to provide radio tuning apparatus involving simple parts which are inexpensive to manufacture requiring low tooling costs and not requining accurate machine work to close tolerance and wherein loose tting parts and play between parts do not affect accuracy of tuning.

A still further object of the present invention is to provide control apparatus particularly adapted for tuning radio apparatus, which control apparatus has a movable or indexing member of relatively low mass therefore requiring mini- Y mum manual energy for tuning,

. provide tuning apparatus involving a single push- A further object of the present invention is to provide a self contained, rigid tuning unit that may be readily coupled to a, radio frequency coil assembly or similar control apparatus and which includes visual means for indicating the station tuned.

A further object of the present invention is to button by which any one of a plurality of predetermined radio stations may be tuned in upon successive operation of such pushbutton.

A further object of the present invention is to provide control or `tuning apparatus wherein the movable or indexing member is confined to a given path after the apparatus is assembled making it almost impossible to foul, thereby making the apparatus extremely reliable in operation.

A more specific object of the present invention is to provide a radio tuner including a squirrel cage guide and a coaxially disposed indexing member adapted for camming engagement with Y saidsquirrel cage member, one of said members Y being held stationary while the other is reciprocated relative thereto to effect partial rotation lfrom one station position to the next station position. .Y f

A further object of the present inventiony is .to provide radio tuning apparatus in which the y of a tuning device for a radio receiver.

Figure 2 is a cross-sectional view taken along line II-II of Figure 1.

Figure 3 is a cross-sectional view taken along line III-III of Figure 1.

Figure 4 is an enlarged diagrammatic View of one form of camming arrangement as viewed from the axis of plunger l1 in Figure 1.

Figure 5 is a side view partly in cross-section A of a modication of the radio tuner shown in Figure 1. X

Figure 6 is .a view taken along line VI-VI of Figure 5.

v Figure '7 is a view taken along line VII-VII of Figure 5.

Figure 8 is an enlarged fragmentary view showing the abutting relationship between the indexing member and stop member taken along line VIII--VIII of Figure 1.

I by means of spring 2S.

Figure 9 is an enlarged plan view of one of the stop members shown in Figures 1 and 5.

Figure 10 is a front view of the tuning adjusting device of a further modification shown in Figure l1.

Figure 11 is a cross-sectional view taken along line XI--XI of Figure 10.

Figure 12 is an exploded View of the tuning adjusting knob and associated parts shown in Figures 10 and 11.

Figure 13 is a front view of the squirrel cage element shown in Figure 14.

Figure la is a cross-sectional view taken along line XIV-XIV of Figure 13 showing a modified form of indexing device.

The various figures in the drawings disclose the invention as being embodied in radio receiving apparatus designed especially for use in a vehicle or portable radio. It should be understood, however, that the invention is not so limited and is also adapted foi` other applications.

Referring more particularly to Figures 1 to 4 inclusive, numeral I denotes a pair of guide rods rigidly mounted on suitable support means (not shown) for slidably supporting and guiding a longitudinally reciprocable element 2 normally biased towards the left, as illustrated, by return spring 3 which spring has one end secured to element 2 and the other end xed. It will be apparent that by suitably mounting the structure on end the force of gravity may be substituted for return spring 3. By depression of a station selector pushbutton 5 against the action of spring 6 a switch 'I is closed which completes an energizing circuit through electromagnet coil li, which circuit includes a suitable vsource of electrical energy such as a battery 9. As the result of electromagnetic attraction electromagnet core II! is moved to the right pulling with it stud I I secured thereto as well as the reciprocable element 2 which is rigidly secured to the stud II. By means of suitable linkage such as a crank arm I2 the movable plates of an electrical condenser i3 such as of the 180 type, are partially rotated so as to tune a radio transmitter or receiver circuit having any well known tuning circuit (not shown) which includes condenser I3. It should be noted, however, that a variable inductance might be substituted for condenser I3 for tuning, or if the apparatus is to be used for other purposes than Athat of tuning a radio, such as, for example, to control an electrical system, the variable element of such system may be substituted for condenser I3.

An important feature of the present invention is the specic construction of the squirrel cage element I4 rotatably mounted on bearings I5 and I6 and the reciprocable indexing plunger I'I (see Figures 2, 3 and 8) rigidly secured to element 2 and having a swaged radially directed pin or portion I8. Element I4 is biased towards bearing Pin I8 is adapted to be slid between successive pairs of ribs or guides i9, 20, 2 I, 22, 23, and 24 as the result of successive reciprocation of indexing plunger I'l by virtue of the camming action between the pin and cams such as 25, 26, 21 and 28 (see Figure 4) to be described more fully hereinafter,

Referring more particularly to Figure 4, which shows a development of various guides or ribs as viewed axially of plunger II, in order to make the operation of the device more clearly understood, assume that the plunger Il and associated pin "i3 moves to the right from the full line position. As the pin is strikes cam 25 whichis located near the end of travel of the reciprocable plunger I1 the camming action that results will cause the pin to follow the surface of cam 25 thereby slightly rotating squirrel cage element I4 until the cam 26 is in position to engage the pin I8, the position of said pin with respect to said cam being indicated by the dotted line position Ia which represents substantially the limit of travel of pin I8 to the right as the result of electromagnetic attraction of coil 8. As switch 'I is opened due to release of pushbutton 5 the return spring 3 causes element 2, as well as plunger Il rigidly secured thereto, to move to the left, as illustrated, causing pin I8 to strike cam 26 formed on the end of guide 24 (see position Ib) to effect further rotational movement of squirrel cage element III until the space between the guides 24 and 23 is in registry with the pin i8, the position assumed by said guides with respect to said pin being indicated by reference character IBC. The pin I8 is therefore now located :between the next pair of guides 24 and 23. 'Return :spring 3 will now cause the plunger' I'I to move to the left until pin I8 strikes Aan adjustable stop member, such as the nut portion 48 of stop member 3S illustrated in Fig. 8. By suitable longitudinal adjustment of the position-of stop member 39 along screw threaded shaft 33 a predetermined degree of turning of the movable plates of condenser I3 will be eifected so as to tune in a particular radio station. A plurality oi stops and threaded shafts similar to 39 and 33, respectively, 'are peripherally disposed about the axis of plunger I'I. Figure 2 shows six of such threaded shafts 32 to 31 inclusive representing six diiferent radio stations having preset tuning although it should be understood that any other number of shafts may be used depending upon how many diiferent radio stations are to be tuned in normally. Three of such stops 38, 39 and lo are viewed in Figure 1 and are adjusted to diierent longitudinal positions along the respective threaded shafts to correspond'to different frequencies of tuning, that is, different radio stations y Such longitudinal adjustment of the various stop members is accomplished 'by depressing an adjusting knob 4I against the action of spring 42 so as to move hollow stem 43, having an hexagonal or other suitable shape of socket opening, against a similarly shaped nut portion, such as, for example, 33a, integral with screw shaft 33. By rotating knob 4I and together with it threaded shaft 33 the stop 39 is propelledas a carriage along shaft 33 to the desired position. Likewise other stops may be longitudinally adjusted as the corresponding threaded shaft comes into alignment with stem 43. It should be noted that stem 43 is eccentrically mounted with respect to plunger Il and is rigidly supported by frame AI4 so as to constantly align with whatever shaft assumes the position illustrated by the shaft nut portion 33a in Figure 3. Each complete reciprocation or cycle by electromagnet coil 8 and return spring 3 will cause partial rotation of squirrel cage element I4 so as to move the shaft adjacent shaft 33 into registry with stem 43 and adjusting knob 4 I. By providing a suitable hole (not shown) in frame la which is in alignment with one of the nut por tions other than 33a and by suitably marking said nut portions by numerals or station call letters it may be visually determined which nut or station represented thereby is tuned or is in l `alignment with adjusting nut 4I for adjustment.

"positions after partial rotations thereof.

Thespecic construction ofthe various stop v,members is such as to-provide against drift or vbacklash as the result of frequent reciprocation `of element 2.

against the guides I9 and 24 as stop elements.

This will effect substantially a locking action between the nuts and the threaded shaft 33 so as to 4prevent drift of the nuts and stop member 39 as the result of constant reciprocating movement of element 2 after the stop member 39 has been adjusted. Therefore accurate tuning to dinerent stations is maintained for long periods without the necessity of readjustment from time to time Yas normally required in similar devices `known in the art.

' As described above, successive partial rotations of the squirrel cage element It is achieved by reciprocating plunger Il rigidly secured to the reciprocable element 2. Thus by depression of a single push button the proper number of 'times to obtain the required degree of angular indexing any preset radio station may be tuned in.

An alternative embodiment of the invention is to rigidly secure the squirrel cage element against rotation and allow plunger I'I to rotate about its axis as well as to reciprocate and thus eiect indexing by the camming of vpin I8 against the various cams such as 25, 26, 21etc. l

Such alternative embodiment is illustrated in Figures 5, 6 and 7. The squirrel cage element ill r.of Figures 1, 2 and 3, instead of being rotatably mounted, is, however, rigidly secured by plates 5d and 5l to guide rods IA. Another distinguishing feature is that plunger Il has an end portion 68 which is journaled in reciprocable element 2a so as to allow successive partial rotation of the plunger about its axis as it is reciprocated and as the plunger piny is longitudinally thrust against the various cams during reciprocating movement. A sleeve 52 is loosely mounted on stub shaft 35 so that as the result of each reciprocating cycle and due to the intertting of the right edge of pin I3 into a radial groove in the left end of sleeve 52 the sleeve is rotated in unison with plunger I'I and then held stationary Y after being partially rotated. Sleeve 52 is biased to the left by a spring (not shown) similar to spring 8| in Figure 14. A radially'extending portion of sleeve 52 is perforated to accommodate an adjusting socket 55 secured to the end of a flexible shaft 55, the other end of the flexible shaft having rigidly'secured thereto a tuning adjusting knob 5l. A guide tube 58 surrounds exible shaft 56 and is journaled in a hole extending through indexing plate 59 and in a bearing B8. Indexing plate 59 is rigidly secured to shaft 85, and has a plurality of circumferentially disposed detents (see Figure 6) adapted to engage a bent end portion of index spring El so as to' aid in maintaining sleeve 52 in xed angular An outstanding advantage in having the plunger `Il' as the indexing member is thatit has relatively light mass and requires minimum energy to reeiprocate. n shmud be noted that the eamming *8 action takes place while pin I8 is traversing vthe length of the radially grooved portion of sleeve 52 similar to the construction shown in Figure 14 to be described hereinafter.

A second index plate 62 having .a plurality of peripherally disposed numerals, (or station call g letters) one numeral corresponding to each station, is rigidly secured to guide tube 53. The main panel 64 has an yaperture B5 with which the various numerals on plate 62 are adapted to come "into registry upon successive partial rotations of plunger I1 about its axis thereby giving the operator a visual indication of the station to be adjusted as will appear in Figure 7.

Figures 10 to 14 inclusive show a further modiiication of the invention which is similar to that shown in Figure 5 in that the squirrel cage element is held stationary and the plunger I'IA is mounted so as to rotate about its axis as it is reciprocated due to camming action. Knob 68 is resiliently supported by a garter spring or plastic band 69 which i-lts into an annular groove in the snap-in bezel 'I0 which, in turn, is resiliently supported on the main panel 'II by means of spring clips 12. As will be noted in Figure 10 knob 68 is` eccentrically mountedr with respect to plunger ITA- also element 'In is perforated so that numerals appearing on the end of set-up screw heads I3 may be viewed to indicate the Station which is selected. When it isdesired to adjust the position of the stop members knob 68 is pushed in so its socket end will engage the set-up screw head aligned therewith. Different station adjustments may be made by removing element 18 and using knob 68 as a socket wrench.

Referring to Figure 14, it will be noted that laterally projecting portions 'Ill and l5 extending from fiat plates or Stampings I5 and ll, respectively, serve as the cam members 25, 2l, etc. illustrated in Figure 4. Edges *I8 and 'I9 are beveled and correspond to cams 26 and 28 in Figure 4. A position indicating member comprises a stem 88 with suitable notches for engaging the end portion of leaf spring 8l and has an integral disc portion 82 with numerals peripherally disposed thereon (see Figure 13) which may be viewed by the operator through the aperture in element 10.

Pin I 8A is adapted to engage a grooved portion of stem 8D so as to rotate the stem upon reciprocation of plunger IIA so asV to cause disc portion 82 to rotate with plunger I'IA and thus indicate each successive tuning position. It

should be noted that the camming action or indexing occurs during the time pin ISA is in transit through the grooved portion of stem 88.

As indicated previously, the invention while described as a radio tuner is also suitable for a wide variety of electrical and mechanicalcon- .trol applications in electrical and mechanical systems other than radio, such as semaphores, power .systems and the like.

vtuning, apparatus is described as operable by successive depression of a single pushbutton it may be also arranged to be operated by multiple pushbuttons if so desired. I have thusprovided an eicient, self-contained, control apparatus suitable as a radio tuner and having a minimum number of simple and inexpensive parts which apparatus is extremely reliable in operation and requires a minimum amount of energy to operate `in viewl of the relatively light movable indexing member.

While 1 have shown a particular embodiment of my invention, it will, of course, be understood that I do not wish to be` limited thereto,` Since many modications may be made, and I, therefore, contemplate by the appended claims to. c over all such modifications as fall within the true spirit and scope of my invention.

I claim as my invention:

l. Mechanism for positioning a control com,- prising a squirrel cage element having a plurality of peripherally disposed guide plates having cam surfaces adjacent one end thereof, a reciprocable plunger disposed coaxially with respect to said squirrel cage element one of said elements being rotatable and the other being held from rotation, and said plunger having aA radially directed portion adapted to slide between said guide plates and engage said cam surfaces to eiect rotational movement of and angular indexing of, .Said rotational element about said plunger axis and longitudinal travel of said radially directed portion between successive paths donned by said plates as the result of reciprocating movement of said plunger.

2. In a mechanism for positioning a control, the combination including a squirrel cage element having a plurality of peripherally disposed, longitudinal guide plates, a reciprocable punger ele ment disposed coaxially Within said squirre cage element and having a radially extending DOIOTI which is guided by said plates, com means adjacent one end of said plates and changeable by said radially extending portion or slightly turn -ing one of said elements about its axis as relative reciprocating motion of said elements is ef- :fectedA in one direction, and a second cam means also engageable with said portion to effect further slight turning of the same element about its axis as relative reciprocating motion of said elements is effected in an opposite direction.

3. in a mechanism for positioning a contr-ol, the combination including a squirrel cage element having a plurality of peripherally disposed longitudinal guide plates, a reciprocable plunger element disposed coaxially within said squirrel cage element and having a radially extending portion which is guided by said plates, said portion inaintaininga constant angular relationship to its axis, cam means adjacent one end of said plates and being engageable by said radially extending portion for slightly turning said squirrel cage element about its axis as said plunger element is longitudinally moved in one direction, and a second cam means adjacent said first cam means for slightly turning said squirrel cage element further in the same direction as said plunger element is moved in an opposite direction.

4. ln a mechanism for positioning a control, the combination including a squirrel cage element having a plurality of peripherally disposed, longitudinal guide plates, a reciprocable plunger element disposed coaxially with respect to said squirrel cage element an-d having a radially directed portion which is guided by said plates, said plunger element being rotatably mounted about its axis and said kSquirrel cage element being held stationary, cam means adjacent one end of said plates for engagingsaid radially div the combination includinsa squirrel case ele-- CII ment having a plurality of peripherally disposed, longitudinal guide plates,` a reciprocable plunger element disposed coaxially within said squirrel cage element and having a radially extending portion which is guided by said plates, said plunger element being rotatably mounted about its axis and said squirrel cage element being held stationary, cam means for engaging said radially extending portion as said plunger is longitudinally moved in one direction to effect slight turning of said plunger about its axis, and a second cam means engageable with said portion to eiect further rotation in the same direction of said plunger about its axis.

6. Mechanism for positioning a control comprising a squirrel cage element having a plurality or peripherally disposed longitudinal guide plates, a reciprocable plunger element disposed coaxially within said squirrel cage element and having a radially extending portion which is guided by said plates, said plunger element portion being xedly mounted so said portion will retain a constant angular relationship to its axis, and said squirrel cage element being rotatably mounted, cam means engageable by said portion as said plunger element is reciprocated to eiect successive partial rotations of said squirrel cage element about its axis.

1. A tuner for a radio receiver including a squirrel cage element having cam surfaces and a plurality of peripherally disposed Stops, an element disposed coaxially with respect to said squirrel cage element and having a radially directed portion which is adapted to be guided by portions of said squirrel cage element and by said cam surfaces to eiect indexing of one of said elements about its axis as the result of relative reciprocating movement of said elements, said stops being arranged to engage said radially directed portion to limit said reciprocating movements.

8. A tuner for a radio receiver including a squirrel cage element having a plurality of peripherally disposed, longitudinal guide plates, a plurality of stop elements, each located between a pair of said guide plates, a reciprocable plunger disposed coaxially with respect to said squirrel cage element and having a radially directed portion adapted to engage said stop elements to limit longitudinal movement of said plunger, said squirrel cage element also having cam means engageable with said radially directed portion to eiect successive indexing of said plunger about its axis as the result of successive reciprocation thereof within said squirrel cage element.

9, A tuner for a radio receiver including a squirrel cage element having a plurality of peripherally disposed, longitudinal guide plates having cam surfaces adjacent one end thereof, a plurality of peripherally disposed stop elements each located between a pair of said guide plates, a reciprocable plunger disposed coaxially Within said squirrel cage element and having a radially directed portion at a constant angular relationship to said plunger axis and adapted to be guided by said guide plates and cam surfaces so as to effect successive turning of said squirrel cage element about its axis as the result of successive reciprocation of said plunger therein, said stop elements being engageable by said radially directed portion to limit longitudinal movement of said plunger during reciprocation.

10. Control apparatus for an electrical circuit comprising a substantially cylindrical element .having a plurality of longitudinal guide Dls disposed about its periphery, a second cylindrical element coaxially disposed with respect to and surrounded by said first cylindrical element, and having a radially directed portion adapted to be guided by said plates, cam means disposed adjacent one end of said plates for co-operation with said radially directed portion when one of said elements is reciprocated relative to the other to cause relative angular indexing of said members about their axes and movement of said radially directed portion from one longitudinal path be` tween a pair of said plates to an adjacent longitudinal path between one of said pair of plates and a different plate.

11. Radio tuning apparatus including a longitudinally reciprocable tuning element, a squirrel cage element surrounding said tuning element and having a plurality of circumferentially spaced bars and a plurality of spaced stop elements, electromagnet means for moi ing said tuning element in one direction, and spring means tending to move said tuning element in an opposite direction against one of said stop elements, said squirrel cage element including cam means coacting with said tuning element for guiding said tuning velement into successive, adjacent longitudinal paths between said bars as the result of reciprocation of said tuning element;

l2. Radio tuning apparatus comprising a squir= ,rel cage element having a plurality of radially extending, peripherally disposed guide plates, a plurality of longitudinally extending screw threaded shafts rotatable about their axes, one located between each pair of said guide plates, a stop element screw threaded onto each of said shafts, each stop element comprising a pair of adjacent nuts each having two edges conforming to the shape of and guided by adjacent Vguide plates, and a spring having its ends fastened to said nuts and being tensioned so as to tend to move said nuts apart and lock them against the threads of the associated shaft in their adjusted positions as determined by the degree of rotation of said screw threaded shafts, and reciprocable tuning means co-operable with said squirrel cage element for effecting indexing and having an outstanding portion for abutting said stop elements.

13. Radio tuning apparatus comprising a squirrel cage element having a plurality of longitudinal, peripherally disposed guide plates including cam portions, and a tuning element disposed coaxially with and surrounded by said squirrel cage element and having a radially directed portion adapted to he guided by said plates and cam portions so that as the result of successive reciprocations of said tuning element said portion will follow successive adjacent longitudinal paths dened by said plates to eiect angular indexing of said tuning element, indexing means operated by saidltuning element and including a plurality of characters, and panel means having a perforationaligned with one of said characters to give a visual indication of the tuning of said apparatus.

14. Radio tuning apparatus comprising a squirrel cage element and a reciprocable element rotatablydisposed axially thereof and cci-operable therewith to effect successive indexing of said reciprocable element about its axis as the result of successive reciprocations thereof, rotatable `meansfdisposed axially of said reciprocable element and being rotatable thereby and having a plurality of peripherally disposed characters, and a panel having a perforation disposed eccentrically of said rotatable means so as to be in alignof successive reciprocations thereof, said squirrel cage element having a plurality of peripherally spaced stop elements each mounted on one of a plurality of peripherally disposed screw threaded shafts for longitudinal adjustment of said stop elements, a tuning adjusting knob having a tor- -tuous shaft with a socket at the end thereof adapted to be pushed into engagement with a head portion of any of said shafts, and a crank member disposed axially of and indexed by said reciprocable element to effect alignment of said socket with successive head portions of said shafts.

16. In a tuning apparatus, a squirrel cage element having a plurality of angularly spaced cam surfaces extending transversely of its longitudinal axis, alternate of which cam surfaces face in opposite directions, a rectilinearly movable plunger element mounted coaxially of said squirrel cage element, one of said elements being rotatable and the other being held from rotation, means selectively operable to move said plunger in one direction and other means moving said plunger in an opposite direction, and said plunger having a radially directed portion having coacting engagement with one of said cam surfaces when moving in one direction and with another of said cam surfaces when moving in an opposite direction to successively rotate one of said elements with respect to the other from one indexed position to another upon each reciprocation of said plunger. Y

17. In a tuning apparatus, a squirrel cage element having a plurality of angularly spaced guide plates having facing oppcsitely extending cam surfaces adjacent one of their ends and extending transversely of the longitudinal axis of said squirrel cage element, alternate of which cam surfaces extend into the spaces between said guide plates, a rectilinearly movable plunger element mounted coaxially of said squirrel cage element, one of said elements being rotatable and the other being held from rotation, means selectively operable to move said plunger in one direction and yieldable means urging said plunger to move in an opposite direction, said plunger ,having a radially directed portion slidable between said guide plates into engagement with one of said cam surfaces when moving in one direction and movable into engagement with another carn surface yand into the space between the next adjacent guide plates when moving in an opposite direction.

DONALD HOWARD MILLS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 95,586 Henderson Oct. 5, 1869 2,342,691 Plensler Feb. 29, 1944 2,343,219 Marholz Feb. 29, 1944 

